Steps to reproduce the issue

Install a 4.2 package.

Go to a list view that includes more than 2 records and uses multiselect.js, for example the update extensions installer:
http://root/administrator/index.php?option=com_installer&view=update

Select one of the checkbox.

Expected result

Only that checkbox is checked

Actual result

The same checkbox and the next one is checked. 2 checkbox are checked at once.

System information (as much as possible)

The error is due to this change in the file multiselect.js, line 16.

Joomla 4.1 OK:
this.boxes = [].slice.call(this.tableEl.querySelectorAll('input[type=checkbox]'));

Joomla 4.2 ERROR:
this.boxes = [].slice.call(this.tableEl.querySelectorAll('td input[type=checkbox]'));